The Oakland Athletics activated pitcher Taylor Thompson from the 60-day disabled list and optioned him to Triple-A Nashville on Sunday, according to the Bay Area News Group. Thompson has not pitched for the big club this season as he continues to recover from a shoulder injury, and will continue his rehabilitation in the minors before a potential September call-up.

Thompson (shoulder) is set to throw 20 pitches during batting practice Thursday, Susan Slusser of the San Francisco Chronicle reports. After his bullpen sessions last week went without a hitch, Thompson will advance to the next phase of his rehab. If Thursday's activity goes well, he could embark on a rehab assignment at a minor-league affiliate while the Athletics remain on break for the All-Star Game.

Thompson (shoulder) threw a 35-pitch bullpen session Monday, Jane Lee of MLB.com reports. The A's were satisfied with the results of the session, and the expectation is that Thompson will move on to facing live hitters in the near future. Thompson, who was placed on the 60-day DL back in February, remains without a return timetable.

Thompson (shoulder) was placed on the 60-day DL on Thursday. A shoulder strain will put Thompson on the shelf for an extended period, though a specific timetable for his return has not been established. The right-hander was able to overcome his control issues with the White Sox's Triple-A Charlotte affiliate last season, posting a 2.14 ERA and 10.4 K/9 despite a 4.4 BB/9 rate over 59 innings. The A's then claimed Thompson off waivers in early November.

The A's claimed Thompson off waivers from the White Sox on Tuesday, Mark Gonzales of the Chicago Tribune reports. After struggling in his first extended audition at Triple-A at the end of 2013 (7.88 ERA), Thompson returned and posted a 2.14 ERA in 39 appearances at that level this past season, though he did take a step backward with his control (4.4 BB/9). Regardless, the A's liked the right-hander enough to take a flier on him, and they figure to bring the 27-year-old to major league spring training to compete for one of their final bullpen spots. Bryan Anderson was outrighted to Triple-A Nashville to make room on the 40-man roster.